530
Open Access
Asian Australas. J. Anim. Sci.
Vol. 27, No. 4 : 530-536 April 2014
http://dx.doi.org/1 0.571 3/ajas.201 3.1 3527
www.ajas.info
pISSN 1011 -2367 elSSN 1976-5517
Effects of Benzoic Acid and Dietary Calcium:Phosphorus Ratio on
Performance and Mineral Metabolism of Weanling Pigs
A. Gutzwiller*, P. Schlegel, D. Guggisberg, and P. Stoll
Federal Research Institute Agroscope, 1725 Posieux, Switzerland
ABSTRACT: In a 2x2 factorial experiment the hypotiieses tested were tiiat the metabolic acid load caused by benzoic acid (BA)
added to the feed affects bone mineralization of weanling pigs, and that a wide dietary calcium (Ca) to phosphorus (P) ratio in phytase-
supplemented feeds with a marginal P concentration has a positive effect on bone mineralization. The four experimental diets, which
contained 0.4% P and were supplemented with 1,000 FTU phytase/kg, contained either 5 g BA/kg or no BA and either 0.77% Ca or
0.57% Ca. The 68 four-week-old Large White pigs were fed the experimental diets ad libitum for six weeks and were then slaughtered.
Benzoic acid increased feed intake (p = 0.009) and growth rate (p = 0.051), but did not influence the feed conversion ratio (p>0.10).
Benzoic acid decreased the pH of the urine (p = 0.031), but did not affect breaking strength and mineralization of the tibia (p>0.10). The
wide Ca:P ratio decreased feed intake (p = 0.034) and growth rate (p = 0.007) and impaired feed the conversion ratio (p = 0.027), but
increased the mineral concentration in the fat-free DM of the tibia (p = 0.013) without influencing its breaking strength (p>0.10). The
observed positive effect of the wide Ca:P ratio on bone mineralization may be attributed, at least in part, to the impaired feed conversion
ratio, i.e. to the higher feed intake and consequently to the higher mineral intake per kg BW gain. The negative impact on animal
performance of the wide dietary Ca:P ratio outweighs its potentially positive effect on bone mineralization, precluding its
implementation under practical feeding conditions. (Key Words: Benzoic Acid, Calcium, Bone Characteristics, Pig)
INTRODUCTION
Pig slurry contributes to the environmental pollution by
phosphorus (P) and nitrogen, part of which is evaporated as
ammonia. In regions with a high pig density, pig feeds
commonly contain low amounts of P in order to minimize P
output and are supplemented with phytase to improve
intestinal P absorption. Ammonia emission from pig slurry
can be reduced by supplementing the feed with benzoic acid
(BA). Benzoic acid inhibits microbial ammonia formation
via its metabolite hippuric acid, which is formed in the liver
and excreted in the urine (Hansen et al., 2007). Benzoic and
hippuric acid contribute to the metabolic acid load and may
therefore affect bone integrity, because chronic acidosis
stimulates bone resorption by osteoclasts and compromises
* Corresponding Author: A. Gutzwiller Tel: -1-41-26-407-72-23,
Fax: -1-41-26-407-73-00, E-mail: andreas.gutzwiller@agroscope.
admin.ch
Submitted Aug. 22, 2013; Accepted Nov. 19, 2013; Revised Jan. 7, 2014
bone mineralization (Arnett, 2003). In an experiment
reported by Gutzwiller et al. (2011), BA intake had a
negative effect on the bone markers alkaline phosphatase
(AP) and crosslaps in the serum of pigs weighing 25 kg
which were fed a phytase supplemented diet with a low P
concentration, which indicates that BA disturbed bone
metabolism, but later on, at 60 kg BW, neither the bone
markers nor bone mineralization were affected by BA. The
normal bone mineralization of the animals slaughtered at 60
kg BW does not preclude that bone mineralization at a
younger age had been impaired because compensatory bone
mineralization may occur during the growing period
(Fammatre et al., 1977). In order to verify the hypothesis
based on blood traits that BA intake impairs bone
metabolism in weanling pigs fed a diet with a low P
concentration, the animals of the present experiment were
slaughtered at 23+4 kg BW, six weeks after weaning.
The dietary calcium (Ca):P ratio influences bone
mineralization, too. The National Research Council (NRC,
2012) suggests a Ca:P ratio for grain-soybean meal diets
Copyright © 2014 by Asian-Australasian Journal of Animal Sciences
This is an open-access article distributed under ttie terms of ttie Creative Commons Attribution Non-Commercial License {http://creativecommons.Org/licenses/by-nc/3.0/),
which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Gutzwiller et al. (2014) Asian Australas. J.Anim. Sci. 27:530-536
531
between 1.1:1 and 1.25:1 based on the argument that a wide
Ca:P ratio lowers P absorption, growth performance and
bone mineralization. The finding of Lantzsch et al. (1995)
and Letourneau-Montminy et al. (2010) that increasing the
Ca:P ratio from 1.3:1 to 1.9:1 in diets supplemented with a
high amount of phytase increased P retention and bone
mineralization in weanUng pigs, is in contradiction to the
NRC recommendation. In these two balance studies the
digestibility of both Ca and P was 70%, resulting in a ratio
of absorbed Ca to absorbed P which corresponded to the
dietary Ca:P ratio. Because the ratio of Ca:P retained in the
body of growing pigs is 1.65:1 (Crenshaw, 2001), Ca
absorbed from the phytase supplemented diets with a Ca:P
ratio of 1.3:1 presumably became the hmiting factor for
bone mineralization. The negative effects of the wide
dietary Ca:P ratio on growth performance stated by the
NRC (2012) could not be verified in the balance studies of
Lantzsch et al. (1995) and of Letourneau-Montminy et al.
(2010) because feed intake of the pigs had been restricted.
In the present study the effects of two Ca:P ratios in phytase
supplemented diets on growth performance and bone traits
were therefore studied in ad libitum fed weanUng pigs kept
in groups. Because BA increases the absorption, but also the
renal excretion of P (Gutzwiller et al., 2011) and may
therefore interact with the effects of the dietary Ca:P ratio,
the effects of both factors were studied together in a 2x2
factorial experiment.
MATERIALS AND METHODS
The experiment was approved by the animal welfare
department of the canton of Fribourg, Switzerland (approval
number FR 4/10).
Experimental design and diets
The effects of two factors, BA and dietary Ca
concentration, were examined in a 2x2 factorial experiment
using 32 female and 36 castrated male weanling pigs.
Groups of four littermates of the same gender with a similar
BW were blocked. Each pig within a block was randomly
assigned to one of the four dietary treatments. The four
experimental diets had the same P concentration, but either
a high (HCa) or a low (LCa) Ca concentration. Diets HCa-
and LCa- contained no BA. For the production of diets
HCa-H and LCa-n containing 0.5% BA, 2.5 kg BA
(VevoVitall, DSM Nutritional Products Ltd., Basel,
Switzerland) plus the amount of ingredients necessary for
the production of 500 kg diets HCa- and LCa- respectively
were mixed in the feed mill during the feed blending
process.
Based on the analyzed DM, CP, crude fat, crude fiber
and ash content of the batches of ingredients available for
blending the feeds plus feed table data of their mineral and
apparent digestible P (dP) content and their digestible
amino acid composition the diets were formulated to have
the same energy and nutrient content, except for Ca. The
formulated dietary nutrient content corresponded to the
Swiss recommendations for pigs weighing 15 kg
(Agroscope Liebefeld-Posieux, 2004) except for their lower
than recommended apparent total tract dP content of 0.27%,
which was calculated using the tabulated P digestibility data
of the ingredients (Agroscope Liebefeld-Posieux, 2004) and
a dP equivalence of 1.2 g for the 1,000 FTU of added
phytase/kg diet (Kornegay, 2001). The four experimental
diets were mixed in the feed mill of the institute using
ingredients of the same batch. The meal was pelleted at
70°C in order to prevent thermal inactivation of native and
supplemented phytase. The dietary electrolyte balance
(dEB), expressed as milliequivalents (mEq)/kg diet, was
calculated by subtracting mEq chloride (Cl)/kg from the
sum of mEq sodium (Na)/kg plus mEq potassium (K)/kg.
Animals and husbandry conditions
The 68 Large White pigs weighing on average 9.7 kg
entered the experiment on the day of weaning at the age of
four weeks. They were equipped with transponders for
individual identification by the computer controlled feeding
station and were transferred to four identical pens (one per
treatment) with 7 m^ slatted floor and 10 m^ concrete floor
with straw bedding, which were situated in one room of a
climate controlled building. Each pen was equipped with
one feeding station (Schauer, Prambachkirchen, Austria)
having one feed trough for the feeding of one pig per visit.
Visiting piglets were identified and could eat from the
trough standing on a scale which registered feed
disappearance per visit. The pelleted diets were available ad
libitum during the experiment lasting 41 days. Three nipple
drinkers per pen provided tap water. The technical
installations and the piglets were checked daily by the
attendants.
Experimental procedures
Feed samples were collected at the end of each
experimental week, and the six samples of each diet were
pooled for nutrient analysis. The pigs, which had constant
access to feed and water until the end of the experiment,
were weighed weekly and at the end of the experiment.
Within two hours after the last weighing they were killed at
the slaughterhouse situated on the premises of the research
institute. They were stunned with CO2, and at sticking
blood samples were collected into tubes without
anticoagulant. During evisceration urine samples were
collected from the bladder of 33 animals (IICa+: 9 pigs;
HCa-, LCa+, LCa-: 8 pigs per treatment); the bladders of 35
animals contained no urine. The blood samples were
centrifuged within two hours after collection. Both tibiae
532
Gutzwiller et al. (2014) Asian Australas. J.Anim. Sci. 27:530-536
were collected within half a day after slaughter, manually
cleaned of adhering tissue and packed in sealed plastic bags.
The bones, serum and urine samples except the samples for
urinary pH determination were stored at -20°C until they
were analyzed.
Laboratory procedures
Urine pH was determined within half an hour after
collection using a Metrohm pH 691 meter (Metrohm,
Zofmgen, Switzerland). The left tibiae were transferred
from the freezer to a refrigerator having a temperature of
10°C 16 h before their breaking strength was determined
using the three point bending test. The bones were held on a
testing machine (Zwick Roell, Ulm, Germany) by two
supports spaced 49 mm apart and were broken by a wedge
lowered on the centre of the bone at a speed of 10 nrai/min.
The peak of maximum force was recorded. After
autoclaving the right tibiae at 121°C and 1 atmosphere
during 45 min, the adhering soft tissue was removed, the
bones were crushed, bathed for four hours in acetone under
constant stirring for defatting and ground through a 3 mm
screen. Samples of defatted ground bone and of feed were
dried at 105°C for the determination of the DM. Bone and
feed samples were ashed in a muffle furnace at 550°C. The
ashed bone and feed samples were solubilized in 10 molar
nitric acid, and their Ca, P, magnesium (Mg), Na and K
concentrations were analyzed according to EN 15510:2007
using an inductively coupled plasma optical emission
spectrometer (ICP-OES, Optima 2000 DV, Perkin-Elmer,
Schwerzenbach, Switzerland). Phytate phosphorus in the
diets was analyzed using the kit K-Phyt 12/12 (Megazyme,
Bray, Ireland). Dietary chloride concentration was analyzed
using the argentometric titration method. CP was analyzed
using the Dumas method on a Leco FP-2000 analyzer (Leco,
Monchengladbach, Germany). For amino acid
determination, the feed samples were prepared according to
the Commission Regulation (EC) 152:2009 and were
analyzed by HPLC (Alliance 2695, Waters, Milford, MA,
USA) as described in the manufacturer's manual (Waters
AccQ Tag Chemistry Package 052874 TP, rev. 1). Crude
fiber and crude fat were analyzed according to the
VDLUFA methods 6.1.4 and 5.1.1. Phytase activity in the
feeds was measured using the ISO 30024 method (Gizzi et
al., 2008). One FTU corresponds to the amount of enzyme
that releases 1 |Limol P from 5 mM phytate/min at pH 5.5
and 37°C. The serum and urine analytes were assayed on an
Cobas Mira analyzer (Roche, Basel, Switzerland) at 37°C,
using kit 1489216 for Ca (Roche, Basel, Switzerland),
61571 for P (BioMerieux, Marcy I'etoile, France),
11489291 for creatinine (CREA Roche) and 2172933 for
alkaline phosphatase (AP; Roche).
Statistical analysis
The individual pig served as the experimental unit. The
data were analyzed with the ANOVA procedure of the
statistics package NCSS 2007 (Hintze, Kaysville, Utah,
USA) using the general Unear model. The model included
BA (+, -), dietary Ca concentration (HCa, LCa) and the
BAxCa interaction as fixed factors, and block as random
factor. The block effect was not included in the model for
the analysis of the urine variables because of missing data.
Because the pigs of treatments HCa had a significantly
lower final BW and consequently also smaller,
mechanically less resistant tibiae than the pigs of treatments
LCa, the force necessary to break the tibia was divided by
the BW of the corresponding animal, and the corrected data
as well as the actually measured data were statistically
analyzed. Differences at p<0.05 were considered
statistically significant, whereas differences with
0.10>p>0.05 were considered as tendency.
RESULTS
The formulation and the chemical composition of the
experimental diets are shown in Table 1 and 2, respectively.
The analyzed nutrient levels corresponded to the formulated
levels. Phytase activity in diets HCa+ and HCa- was 23%
and 32% higher than in diets LCa diets. The calculated
dietary dP concentration amounted to 0.27%.
Growth performance
Benzoic acid increased feed intake (p = 0.009) and
ADG (p = 0.051), but did not influence the feed conversion
ratio (FCR, p>0.10; Table 3). The pigs fed the HCa diets
had a reduced feed intake (p = 0.034), a reduced ADG (p =
0.007) and an impaired FCR (p = 0.027).
Serum and urine variables
Benzoic acid lowered the urinary pH (p = 0.031), but
neither influenced (p>0.10) the other urine nor the serum
variables (Table 4). The pigs fed the HCa diets had an
increased serum Ca (p<0.001) and a decreased serum Mg (p
= 0.002) and P (p<0.001) concentration, whereas serum
alkaline phosphatase activity was unaffected (p>0.10). The
diets HCa increased the urinary Ca/creatinine ratio (p =
0.006), but not the P/creatinine ratio (p>0.10).
Bone traits
Benzoic acid did not influence (p>0.10) any of the bone
traits (Table 5). The mineral concentration in the bone DM
was increased (p = 0.013), and Mg concentration in the
bone ash was decreased (p<0.001) in the pigs fed the HCa
diets, whereas the breaking strength of their bones did not
differ (p>0.10) from that of the pigs fed the LCa diets.
Gutzwiller et al. (2014) Asian Australas. J.Anim. Sci. 27:530-536
533
Table 1. Composition of tlie experimental diets with 0.77%
calcium (HCa) and 0.57% calcium (LCa) respectively, as fed
basis
Ingredients (%)
VJVcv rlV^d
v\\(^\ T r'a
i-'iei Lv^ti
Com, ground
4Z.O
4J. /
Barley, ground
ZJ.Z
Oat flakes
3.U
Wheat middlings
n A
n A
U.4
Fat (tallow and lard mixture)
1 n
i.U
U.O
bxpelled soybean meal (450 g Cr/kg)
7.0
6.9
Com gluten feed
1 f\
I.U
Sodium caseinate
O.J
D.J
Whey powder, sweet
J.U
j.U
Apple pomace, dried
5.0
5.0
L-lysine-HCl (79%)
0.21
0.21
L-threonine (99%)
0.06
0.07
Dicalcium phosphate
0.42
0.40
Calcium formate
0.10
0.10
Calcium carbonate
0.61
0.01
Sodium chloride
0.28
0.30
Vitamin trace element premix'
0.40
0.40
Natuphos 5,000
0.02
0.02
Pellan^
0.30
0.30
' Supplied per kilogram of diet: vitamin A, 8,000 lU; vitamin D3, 1,000
lU; vitamin E, 25 mg; menadione, 3 mg; thiamine, 2 mg; riboflavin, 5
mg; biotin, 0.1 mg; niacin, 20 mg; pantothenic acid, 15 mg; iron, 80 mg
as iron sulfate; iodine, 0.15 mg as calcium iodate; copper, 6 mg as copper
sulfate; manganese, 10 mg as manganese oxide; zinc, 75 mg as zinc
oxide; selenium, 0.2 mg as sodium selenite.
^ BASF (Ludwigshafen, Germany); provided 1,000 units Aspergillus niger
phytase/kg diet; one phytase unit corresponds to the amount of enzyme
that releases 1 |rmol P from 5 mM phytate/min at pH 5.5 and 37°C.
' Pellan (Mikro-Technik, Burgstadt, Germany) is a water soluble cellulose
product used to facilitate feed pelleting.
DISCUSSION
Although the low dietary phytate P content of 1.8 g/kg
may have been the limiting factor for the release of P by the
added phytase, the calculated P digestibiUty of 68%
corresponds to previous P digestibility values using similar
diets (Gutzwiller et al., 2011). The calculated dP
concentration of 0.27% in the experimental diets, which
corresponds to 0.19 g dP/MJ DE, is slightly below the 0.20
g dP/MJ DE required by pigs weighing 11 to 25 kg (NRC,
2012). The lower than recommended dietary dP
concentration, which corresponds to levels used in Swiss
pig feeds formulated to minimise P effluent, was chosen in
order to detect possible dietary effects under the condition
of a marginal P supply. It is known that the effect of
different dietary Ca:P ratios on growth performance and
bone characteristics is more pronounced at marginal
compared to high dietary P levels (Reinhardt and Mahan,
1986; Hall et al., 1991). Despite the marginal dP supply, the
bone ash concentration of the experimental animals
corresponds to the concentration of 50% to 53% ash in the
fat-free DM reported by Koch et al. (1984), Traylor et al.
(2005) and Adeola et al. (2006) in weanling and growing
pigs fed diets containing adequate Ca and P levels.
The difference in phytase activity between diets HCa
and LCa cannot be exclusively accounted for by the
uncertainty of the analytical method used, which has a
relative standard deviation for reproducibility of 15% (Gizzi
et al., 2008). The reason for the larger than expected
difference is unknown. Although BA had increased P
digestibility in a previous experiment (Gutzwiller et al.,
2011), and therefore might have modulated the effects of
the Ca:P ratio on animal performance and mineral
metabolism, no significant BAxCa interaction on any of the
tested parameters was observed in the present experiment.
The effects of the two factors are therefore discussed
separately.
Effects of benzoic acid
Benzoic acid increased the growth performance of the
pigs, confirming the results of previous studies
(Guggenbuhl et al., 2007; Torrallardona et al., 2007).
Although BA significantly lowered the urinary pH from 7.4
to respectively 7.1 and 6.5 in treatments HCa-n and LCa-H,
the values of the pigs receiving the BA supplemented diets
corresponded to the urinary pH of pigs exposed to a
physiological dietary acid load (Budde and Crenshaw,
2003) and therefore reflect an undisturbed acid-base
balance. Torrallardona et al. (2007) and Gutzwiller et al.
(2011) reported urinary pH values below 5.5 in weanling
pigs which were fed diets containing 0.5% BA. The higher
dEB (135 vs 82 mEq/kg) and the higher Ca concentration
(5.7 and 7.7 g/kg vs 5.3 g/kg) in the diets of the present
compared to those of the previous experiment account for
the higher urinary pH in the present compared to our
previous experiment because both a high dEB and a high
dietary Ca concentration increase the urinary pH in pigs
(Canh et al., 1998). The fact that BA neither affected the
serum AP activity, which is in contrast to our previous
finding (Gutzwiller et al., 2011), nor the bone traits,
suggests that BA does not impair bone metabolism of
weanling pigs unless its addition decreases urinary pH to
below 6, a value associated with a reduced Ca retention in
pigs (Patience and Chaplin, 1997).
The absence of any negative BA effect on bone
characteristics confirms the findings of Sauer et al. (2009)
and of Gutzwiller et al. (2011), who did not detect any
negative effect of BA on bone ash concentration and
breaking strength in pigs weighing 40 and 60 kg,
respectively. The effects of BA on bone traits of growing-
finishing pigs reported by Biihler et al. (2010) are
equivocal: Benzoic acid tended to reduce ash concentration
in the metatarsal bones, but did not affect the breaking
534 Gutzwiller et al. (2014) Asian Australas. J. Anim. Sci. 27:530-536
Table 2. Chemical composition of the four experimental diets, % as fed basis unless stated otherwise
Ca concentration
Item High (HCa) Low (LCa)
+
+
CP
17.1
16.8
17.1
17.0
Crude fat
3.5
3.8
4.0
3.5
Crude fiber
2.7
3.0
2.8
2.9
Ash
4.3
4.3
3.8
3.8
Calcium
0.76
0.78
0.55
0.58
Phosphorus
0.39
0.41
0.41
0.41
Phytate phosphorus
0.17
0.18
0.20
0.18
Magnesium
0.11
0.11
0.11
0.11
Potassium
0.52
0.53
0.54
0.55
Sodium
0.23
0.23
0.24
0.25
Chloride
0.36
0.36
0.36
0.37
Phytase activity (FTU/kg)
1,450
1,350
1,100
1,100
Lysine
1.10
1.10
1.08
1.08
Methionine
0.36
0.37
0.37
0.36
Cystine
0.27
0.27
0.28
0.28
Tryptophan
0.20
0.20
0.21
0.21
Threonine
0.74
0.74
0.72
0.72
DE (MJ/kg)
14.0
14.0
14.0
14.0
Calcium:phosphorus ratio
1.9
1.9
1.3
1.4
Dietary electrolyte balance (mEq/kg)
129
133
139
141
DE, calciumiphosphorus ratio and dietary electrolyte balance (Na*+K*-Cr, expressed in milliequivalents) were calculated while the other data represent
analyzed values.
Strength of the tibia, despite a significantly reduced tibial
concentration of at least 2.5 mmol/L. All but one of the pigs
bone mineral density. In conclusion.
the majority of
fed the LCa diets, but only two thirds of the pigs fed the
published data do not show significant negative effects of
HCa diets had a serum P concentration above that threshold
BA on bone breaking strength and bone ash concentration.
concentration, which may explain
the growth-depressing
suggesting that the risk of reduced bone mineralization
effect of the
: HCa
diets. An increase in serum Ca
caused by this feed additive is low.
concentration.
as observed in the
pigs fed diets HCa, is
known to
decrease serum
parathyroid hormone
Effects of the dietary Ca:P ratio
concentration
and
to increase serum calcitonin
The effects of the wide dietary Ca:P ratio in diets HCa
concentration (Cooper et al., 1971), resulting in a reduced
on feed intake, ADG, FCR as well as
serum Ca and P
renal reabsorption of both Ca and Mg (Littledike and Goff,
concentration confirm results of Lei et al. (1994) and Qian
1987). The increased urinary Caxreatinine ratio observed in
et al. (1996) on the effects of a wide Ca:P ratio in phytase-
treatments HCa shows that urinary Ca excretion was
supplemented weanling pig diets on growth performance
increased in
response to the
increased serum Ca
and serum clinical chemistry. According
to Suttle (2010),
concentration.
The
decreased Mj
I concentration in the
maximum growth in pigs is associated
with a serum P
serum and in the bone ash of the animals on diets HCa may
Table 3. Effects of dietary calcium concentration and benzoic acid (B A) supplementation on j
^rowth performance from four to ten weeks
of age (n = 17)
Ca concentration and BA supplementation
p-value
Item HCa
LCa
SEM
+ -
+
BA
Ca BAxCa
Initial BW (kg) 9.7 9.6
9.8
9.7
0.29
0.793
0.657 0.977
Final BW (kg) 22.7 20.7
24.8
24.3
0.88
0.159
0.012 0.614
ADFI (g) 524 451
567
513
23.8
0.009
0.034 0.691
ADG (g) 329 284
370
343
17.6
0.051
0.007 0.628
FCR' (kg/kg) 1.60 1.64
1.55
1.50
0.044
0.885
0.027 0.334
' FCR = Feed conversion ratio (kg feed consumed per kg BW gain).
Gutzwiller et al. (2014) Asian Australas. J. Anim. Sci. 27:530-536 535
Table 4. Effects of dietary calcium concentration and benzoic acid (BA) supplementation on serum and urine parameters
Ca concentration and BA supplementation
p-value
Item HCa LCa SEM
+ - + - BA Ca BAxCa
Serum (n = 17)
Ca (mmol/L)
2.87
2.89
2.75
2.73
0.030
0.963
<0.001
0.356
Phosphorus (mmol/L)
2.60
2.69
3.47
3.30
0.089
0.648
<0.001
0.155
Magnesium (mmol/L)
1.20
1.21
1.29
1.27
0.022
0.869
0.002
0.458
AlkaUne phosphatase (U/L)
329
332
328
352
17.9
0.434
0.611
0.567
rine'
pH
7.07
7.44
6.46
7.40
0.292"
0.031
0.246
0.322
Ca/creatinine (mmol/mmol)
2.75
3.69
0.96
1.66
0.655'
0.214
0.006
0.855
P/creatinine (mmol/mmol)
0.04
0.05
0.07
0.05
0.009'
0.517
0.183
0.188
' Urine samples could be collected at slaughter from 33 animals only (9 HCa+, 8 of each other treatment).
" SEM of the three treatments with eight repUcations.
be the result of either an increased urinary Mg excretion or
of a decreased intestinal Mg absorption caused by the high
dietary Ca concentration, as observed in the horse (Grace et
al., 2003).
The increased bone ash concentration observed in the
pigs fed diets HCa supports the finding of Letoumeau-
Montminy et al. (2010) that widening the dietary Ca:P ratio
from 1.3 to 1.9 in a diet containing 0.56% P supplemented
with 1,000 FTU/kg phytase had no negative effect on P
digestibility and significantly increased bone ash
concentration in weanling pigs. On the other hand Qian et al.
(1996) reported a negative effect on P digestibility and bone
mineralization of weanling pigs when the Ca:P ratio of a
diet containing 0.45% P supplemented with 1,000 FTU/kg
phytase was increased from 1.2 to 2. A meta-analysis of P
utiUzation in pigs (Letourneau-Montminy et al., 2012)
which shows that increasing dietary Ca negatively affects
retained P when diets have a low concentration of non-
phytate P, but increases retained P in diets having a high
concentration of non-phytate P, explains the conflicting
effects of a wide Ca:P ratio on bone mineralization reported
by Qian et al. (1996) and by Letourneau-Montminy et al.
(2010). The increased bone mineraUzation of the pigs in the
present study fed low P diets with a high Ca concentration
(diets HCa) is in contradiction to the results of this meta-
analysis. P digestibihty was presumably less impaired than
FCR by the wide Ca:P ratio of diets HCa, resulting in an
increased amount of absorbed P per kg BW gain. The
higher phytase activity analyzed in diets HCa, as compared
to diets LCa, may have contributed to the positive effect on
bone mineralization. However, this effect was presumably
of minor importance, because the amount of phytate P
released per unit of phytase markedly dechnes with
increasing dietary phytase concentration (Paditz et al.,
2004).
The hypothesis tested that the Ca:P ratio in phytase-
supplemented feeds for growing pigs should be wider than
1.3:1 in order to meiximise bone minerjilization could not be
verified in the present study because the effects of the
increased Ca supply, of the reduced feed conversion ratio
and the differences in dietary phytase activities on bone
mineralization cannot be separated. However, the results
show that a dietary Ca:P ratio of 1.9:1 in a low P diet
reduces growth performance to such an extent that such a
feeding regimen cannot be recommended for economic
reasons. The question as to the effects of Ca:P ratios wider
than 1.3:1 but lower than 1.9:1 in phytase supplemented
low P diets on growth performance, Ca and P digestibility
and bone mineraUzation merits further investigation.
Table 5. Effects of dietary calcium concentration and benzoic acid (BA) supplementation on characteristics of the tibia (n = 17)
Ca concentration and BA supplementation
Item HCa LCa SEM
+
+
BA
Ca
BAxCa
Breaking strength (N^)
1,329
1,266
1,377
1,341
46.7
0.298
0.192
0.779
Breaking strength (N/kg BW)
57.8
59.4
55.7
56.7
1.62
0.426
0.142
0.857
Ash (% in fat free DM)
53.1
53.3
51.4
51.2
0.74
0.952
0.013
0.776
Calcium (% in ash)
40.6
39.5
39.5
39.3
0.41
0.132
0.129
0.246
Phosphorus (% in ash)
19.1
19.1
19.4
19.0
0.20
0.361
0.548
0.283
Magnesium (% in ash)
0.90
0.92
0.98
0.98
0.02
0.833
<0.001
0.534
' N = Newton.
536
Gutzwiller et al. (2014) Asian Australas. J.Anim. Sci. 27:530-536
REFERENCES
Adeola, O., O. A Olukosi, J. A. Jendza, R. N. Dilger, and M. R.
Bedford. 2006. Response of growing pigs to Peniophora lycii-
and Escherichia co/i-derived phytases or varying ratios of
calcium to total phosphorus. Anim. Sci. 82:637-644.
Agroscope Liebefeld-Posieux (ALP). 2004. Apports alimentaires
recommandes et tables de la valeur nutritive des aliments pour
pores. LMZ, Centrale des Moyens d'Enseignement Agricole,
Zollikofen, Switzerland.
Amett, T. 2003. Regulation of bone cell fiinction by acid-base
balance. Proc. Nutr. Soc. 62:511-520.
Budde, R. A. and T. D. Crenshaw. 2003. Chronic metabolic acid
load induced by changes in dietary electrolyte balance
increased chloride retention but did not compromise bone in
growing swine. J. Anim. Sci. 81:197-208.
Buhler, K., A. Liesegang, B. Bucher, C. Wenk, and J. Broz. 2010.
Influence of benzoic acid and phytasc in low-phosphorus diets
on bone characteristics in growing-finishing pigs. J. Anim. Sci.
88:3363-3371.
Canh, T. T., A. J. A. Aarnink, Z. Mroz, A. W. Jongbloed, J. W.
Schrama, and M. W. A. Verstegen. 1998. Influence of
electrolyte balance and acidifjdng calcium salts in the diet of
growing-finishing pigs on urinary pH, slurry pH and
volatilisation from slurry. Livest. Prod. Sci. 56:1-13.
Cooper, C. W., L. J. Deftos, and J. T. Potts. 1971. Direct
measurement of in vivo secretion of pig thyrocalcitonin by
radioimmunoassay. Endocrinology 88:747-754.
Crenshaw, T. D. 2001. Calcium, phosphorus, vitamin D, and
vitamin K in Swine nutrition. In: Swine Nutrition, 2"'' Ed. (Ed.
A. J. Lewis and L. L. Southern). CRC Press, Boca Raton, pp.
187-212.
Fammatre, C. A., D. C. Mahan, A. W. Fetter, A. P. Grifo, and J. K.
Judy. 1977. Effects of dietary protein, calcium and phosphorus
levels for growing and finishing swine. J. Anim. Sci. 44:65-71.
Gizzi, G, P Thyregod, C. von Hoist, G Bertin, K. Vogel, M.
Faurschol-lsaksen, R. Betz, R. Murphy, and B. Brandt. 2008.
Determination of phytase activity in feed: Interlaboratory study.
J. AOAC Int. 91:259-267.
Grace, N. D., C. W. Rogers, E. C. Firth, T. L. Faram, and H. L.
Shaw. 2003. Digestible energy intake, dry matter digestibility
and effect of calcium intake on bone parameters of
thoroughbred weanlings in New Zealand. NZ Vet. J. 51:165-
173.
Guggenbuhl, P., A. Seon, A. Pinon Quintana, and C. Simoes Nunes.
2007. Effects of dietary supplementation with benzoic acid
(VevoVitall®) on the zootechnical performance, the
gastrointestinal microflora and the ileal digestibility of the
young pig. Livest. Sci. 108:218-221.
Gutzwiller, A., H. D. Hess, A. Adam, D. Guggisberg, A. Liesegang
and P. StoU. 2011. Effects of a reduced calcium, phosphorus
and protein intake and of benzoic acid on calcium and
phosphorus metabolism of growing pigs. Anim. Feed Sci.
Technol. 168:113-121.
Hall, D. D., G L. Cromwell, and T. S. Stahly. 1991. Effects of
dietary calcium, phosphorus, calcium:phosphorus ratio and
vitamin K on performance, bone strength and blood clotting
status of pigs. J. Anim. Sci. 69:646-655.
Hansen, C. F., G Sorensen, and M. Lyngbye, 2007. Reduced diet
crude protein, benzoic acid and inuhn reduced ammonia, but
failed to influence odor emission from finishing pigs. Livest.
Sci. 109:228-231.
Koch, M. E., D. C. Mahan, and J. R. Corley. 1984. An evaluation
of various biological characteristics in assessing low
phosphorus intake in weanling swine. J. Anim. Sci. 59:1546-
1556.
Komegay, E. T. 2001. Digestion of phosphorus and other
nutrients: the role of phytases and factors influencing their
activity. In: Enzymes in Farm Animal Nutrition (Ed. M. R.
Bedford and G G Partridge). CAB International, Wallingford,
UK. pp. 237-271.
Lantzsch, H. J., S. Wjst, and W. Drochner. 1995. The effect of
dietary calcium on the efficacy of microbial phytase in rations
for growing pigs. J. Anim. Physiol. Anim. Nutr. 73:19-26.
Lei, X. G, P K. Ku, E. R. Miller, M. T. Yokoyama, and D. E.
UUrey. 1994. Calcium level affects the efficacy of
supplemental microbial phytase in com-soybean meal diets of
weanling pigs. J. Anim. Sci. 72:139-143.
Letoumeau-Montminy, M. P., A. Narcy, M. Magnin, D. Sauvant, J.
F. Bemier, C. Pomar, and C. Jondreville. 2010. Effect of
reduced dietary calcium concentration and phytase
supplementation on calcium and phosphorus utilization in
weanling pigs with modified mineral status. J. Anim. Sci.
88:1706-1717.
Letoumeau-Montminy, M. P., C. Jondreville, D. Sauvant, and A.
Narcy. 2012. Meta-analysis of phosphorus utilization by
growing pigs: Effect of dietary phosphorus, calcium and
exogenous phytase. Animal 6:1590-1600.
Littledike, E. T. and J. Goff. 1987. Interactions of calcium,
phosphorus, magnesium and vitamin D that influence their
status in domestic meat animals. J. Anim. Sci. 65:1727-1743.
National Research Council. 2012. Nutrient Requirements of Swine.
11th Ed. National Academy Press, Washington, DC.
Paditz, K., H. Kluth, and M. Rodehutscord. 2004. Relationship
between graded doses of three microbial phytases and
digestible phosphorus in pigs. Anim. Sci. 78:429-438.
Patience, J. F. and R. K. Chaplin. 1997. The relationship among
dietary undetermined anion, acid-base balance, and nutrient
metabolism in swine. J. Anim. Sci. 75:2445-2452.
Qian, H., E. T. Komegay, and D. E. Conner. 1996. Adverse effects
of wide calcium:phosphoms ratios on supplemental phytase
efficacy for weanling pigs fed two dietary phosphorus levels. J.
Anim. Sci. 74:1288-1297.
Reinhardt, G. A. and D. C. Mahan. 1986. Effects of various
calcium:phosphorus ratios at low and high dietary phosphoms
for starter, grower and finishing swine. J. Anim. Sci. 63:457-
466.
Sauer, W., M. Cervantes, J. Yanez, B. Araiza, G Murdoch, A.
Morales, and R. T. Zijlstta. 2009. Effect of dietary inclusion of
benzoic acid on mineral balance in growing pigs. Livest. Sci.
122:162-168.
Sutfle, N. 2010. Mineral Nutt'ition of Livestock. 8th Ed. CABI,
Wallingford, GB.
Torrallardona, D., I. Badiola, and J. Broz. 2007. Effects of benzoic
acid on performance and ecology of gastrointestinal
microbiota in weanling piglets. Livest. Sci. 108:210-213.
Traylor, S. L., G L. Cromwell, and M. D. Lindemann. 2005.
Bioavailability of phosphorus in meat and bone meal for swine.
J.Anim. Sci. 83:1054-1061.
Live Music Archive
Librivox Free Audio
Metropolitan Museum
Cleveland Museum of Art
Internet Arcade
Console Living Room
Books to Borrow
Open Library
TV News
Understanding 9/11